Cylinder head for internal combustion engines



J 1934- A. H. R. FEDDEN 1,962,987

CYLINDER HEAD NOR INTERNAL COMBUSTION ENGINES Filed Aug. 28, 1931 2Sheets-Sheet 1 Fig.1. &

June 12, 1934. R. bD N 1,962,987

CYLINDER HEAD FOR INTERNAL COMBUSTION ENGINES Filed Aug. 28, 1931 2Sheets-Sheet 2 Patented June 12, 1934 UNITED STATES CYLINDER HEAD FORINTERNAL CODIBUSTION ENGINES Alfred Hubert Boy Fedden, Bristol, England,as-

signor to The Bristol Aeroplane Company Limited, Bristol,

England, a British company Application August 28, 1931, Serial No.

In Great Britain September 30, 1930 6Claims.

This invention is for improvements in or relating to cylinder heads forinternal combustion engines and has for its object to provide animproved construction of cylinder head of the kind having a recessextending into the cylinder.

Such cylinder heads are commonly used in internal combustion engines ofthe kind in which the inlet and exhaust ports are controlled by areciprocating and/or rotating sleeve, and it is found difficult toprovide efllcient cooling for the cylinder head of an engine of thiskind, since there is no flow of air or gas through the cylinder head.

It has been proposed to provide means for 16 directing a stream of airinto the recess of a cylinder head of the kind described but, accordingto this invention, a recessed cylinder head for an internal combustionengine is provided with a guide or deflector for directing a stream ofair into the recess, which guide or deflector is formed integrally withthe cylinder head. An advantage of such a construction is that heat isconducted from the cylinder head to the guide or deflector which thusassists in the cooling.

Preferably, according to the invention, a deflector or guideconstitutes, with the walls of the recess, two chambers whereof one isdisposed round the sides and bottom of the recess and the other occupiesthe central part of the recess. With a cylinder head constructed in thisway two streams of air may be caused to enter the recess, one passinground the wall of the recess and the other passing into and out of thecentral part of the recess.

A particular form of construction of cylinder head according to thisinvention will now be described as applied to an air-cooled sleeve-valveaeroplane engine, with reference to the accompanying drawings, of which:

Figure 1 is a sectional elevation of a cylinder head according to theinvention showing parts of the cylinder, a piston and sleeve-valve inposition,

Figure 2 is a sectional elevation at right-angles to Figure 1 but withcertain parts omitted,

Figure 3 is a plan view of the cylinder head corresponding to Figure 2,

Figure 4 is a view similar to Figure 2, showing the sparking plugs andcover plates in position, whilst Figure 5 is an elevation correspondingto Figure 4, showing the shapes of the cover plates. As shown in Figure1, the cylinder head 10 attached to the cylinder 12 by bolts 11 passingthrough its flange 9; the bolts 11 are also shown in Figure 5. As shown,the cylinder head 10 enters the upper end of the cylinder, leaving theannular space into which the sleeve 14 passes.

A piston 15 reciprocates inside the sleeve 14 and ports 16 and 17 areuncovered and covered at the proper times by the sleeve 14 in knownmanner. The cylinder 12 is furnished with radiating vanes 13.

Built in the recess in the cylinder head 10 are two vertical curvedwalls 18, 19 (see particularly Figure 3).. These walls are so curved asto enclose a space in the middle of the recess, which, in transversesection, is approximately elliptical, and are formed integrally with aseries 7. of parallel partition walls 20, 21, which being formedintegrally with the cylinder head, give rigid support to the curvedwalls l8, 19. The walls 20 and 21 extend from above the open end of therecess right to the bottom, whereas the walls 18, 19 are stopped shortbefore they reach the bottom of the recess, thus forming a series ofports 22, 23 at the bottom of the recess (see Figures 1 and 2).

In addition to the walls or vanes 18, 19, 20 and 21, above-mentioned,the cylinder head is formed with two T-shaped vanes 24, 25 and, as maybe clearly seen from Figures 1 and 3, the leg of the T is a verticalwall, the inner edge of which approaches the elliptical spaceabove-mentioned.

The walls 18, 19, 20, 24 and 25 constitute a guide or deflector for theair entering the cylinder-head recess, as is described below.

All the walls and vanes above-mentioned project a substantial distanceabove the flange 9 of the cylinder head and. a thin plate 26 (seeparticularly Figure 5) is bolted across the cylinder head by extensionsfrom some of the bolts 11. Half of the plate 26 is semi-circular,completely covering its half of the cylinder head while the other halfis annular, leaving a semicircular aperture 34 over one side of thecentral elliptical space on the cylinder-head recess. The sparking plugs28 are covered by a smaller plate 29 which drops into the ellipticalspace between the walls 18 and 19 and fits over the insulation of theplugs and is held in position by nuts 30 engaging studs 31 fitted toupstanding projections 32. It will be seen from Figure 4 that the plate29 divides the recess of the cylinder head into two main spaces, one ofwhich passes round the walls of the recess past the bodies of thesparking plugs and up the other side; the other space is the ellipticalchamber in the centre of no the recess formed between the walls 18 and19.

The cylinder head above desmibed is applicable to radial cylinderengines or to other kinds of engin and in either case a current of airreaches the cylinder head in the direction of the arrow in Figure 3.Part of the air passes down between the walls 20 across the bottom orthe recess and up the other side between the 'walls 21 and out to theatmosphere and another part of the air passes inside the T-shaped vanes24 into the elliptical chamber and out again through the aperture 34.The cover plate 26 serves to guide the air in the desired directions andto spread it over as large an area as possible of the walls 20, 21, 24,25 etc., and since all the parts of the cylinder head are in intimatemetallic contact, heat is rapidly and emciently conducted away from thecylinder head, especially, the sparking plug bodies are efiectivelycooled.

Where the invention is applied to a radial cylinder engine the cylinderswill be arranged with the walls 20 and 21 parallel to the direction offlight. In other types of engines the cylinders are so arranged andsuitable baflles or guides provided, that the air enters each cylinderhead .in the desired direction, as above described.

I claim:

1. An air-cooled internal combustion engine comprising in combination arecessed cylinder head, a deflecting member formed integrally with thecylinder head situated in the recess so as to provide a shallow passageadjacent the walls of the recess and a central space within the saiddeflecting member, guiding means for causing a flow of air into therecess on one side of the deflecting member and out of the recess on theother side of the deflecting member and additional guiding means forcausing an additional flow of air into the central recess.

2. An air-cooled internal combustion engine comprising, in combination,a recessed cylinder head, a deflecting member formed integrally with thecylinder head and situated in the recess so as to provide a shallowpassage adjacent the walls of the recess for cooling air, walls in theadjacent passage, formed integrally with the said deflecting member andwith the cylinder head and arranged parallel to the direction of airflow and a detachable cover plate surmounting the said deflectingmember.

3. An air-cooled internal combustion engine comprising, in combination,a recessed cylinder head, a deflecting member formed integrally with thecylinder head and situated in the recess so as to provide a shallowpassage adjacent the walls of the recess for cooling air, walls in theshallow passage parallel to the direction of air flow and a detachableplate to close the bottom of the central space enclosed by thedeflecting member.

4. An air-cooled internal combustion engine comprising, in combination,a recessed cylinder head, two curved walls formed integrally with thecylinder head and situated within the recess and lying parallel to theaxis of the cylinder so as to enclose a central space in the recess andso as to provide a shallow passage adjacent the walls of the recess forcooling air, integrally formed walls within the shallow passage andparallel to the direction of the air-stream for subdividing the shallowpassage, and a cover plate surmounting the said curved and parallelwalls.

5. An air-cooled internal-combustion engine comprising, in combination,a recessed cylinderhead, a deflecting member formed integrally with thecylinder-head, situated in the recess so as to provide a shallow passageadjacent the walls of the recess for cooling air and protruding abovethe top of the cylinder-head, and a cover-plate surmounting the saiddeflecting member and extending beyond it laterally to provide an inletfor air into the shallow passage.

6. An air-cooled internal-combustion engine comprising, in combination,a recessed cylinderhead, a deflecting member formed integrally with thecylinder-head, situated in the recess so as to provide a shallow passageadjacent the walls of the recess for cooling air and protruding abovethe top of the cylinder-head, walls in the shallow passage parallel tothe direction of airflow, and a detachable cover-plate surmounting thesaid deflecting member and extending beyond it laterally to provide aninlet for air into the shallow passage.

ALFRED HUBERT ROY FEDDEN.

